This invention relates to a weaving welding method utilizing the self-control characteristic of arc, and more particularly to an automatic arc welding position control method in which the peak values of arc currents flowing when the welding torch is brought closest to both ends of weaving are subjected to comparison, so that the position of the welding torch is corrected by regarding the difference between the peak values as the amount of shift of the welding torch relative to the arc generating position, and a device for practicing the method.
In a conventional automatic welding position control method for a weaving welding method in which welding is carried out by a welding torch which is swung right and left above the welding line; arc current is averaged, and a value obtained by integrating the thus averaged arc current for a certain period of time after the welding torch has reached one end of the weaving is subtracted from a value obtained by integrating the averaged arc current for the same period of time after the welding torch has reached the opposite end of the weaving, so that the welding torch is shifted to a correct position above the welding line according to the result of subtraction.
However, the above-described conventional method is still disadvantageous in that, when the weaving period is relatively large, the welding position detecting sensitivity is lowered.